The castle of S. Angelo, fortified in the time of the popes, was built by Hadrian as his mausoleum. The bridge is the ancient _pons Aelius_ of which the parapet is modern, and the statues of SS. Peter and Paul and of angels bearing the instruments of the Passion were added by Clements VII. and IX. It was built by Hadrian to reach his mausoleum. In the middle ages it was lined by a double row of booths, and two hundred people were crushed to death here in the Jubilee of 1450. See pages 32, 239, 242.] Already in the reign of Pius VI. the Romans had imbibed from the French some of the doctrines of the Revolution, among them that of the sovereignty of the people. From that time onwards the papal power could never have been upheld except by foreign arms; and the spirit in which the great Napoleon offered his services should be sufficient evidence that the task of preserving the patrimony of Peter was not undertaken by those whom we ought to regard as having understood better than the Italians the things which belonged to Catholic peace. Every one will admit that the pontifical states were not really independent during these foreign occupations: what appears to be less clear is that a pope-king is not necessarily more free to exercise his high office than a pope who does not rule or who may even be the subject of another government. There is a covered way from the Vatican to Castel Sant' Angelo which is itself a parable of the history of the Roman popes. It was constructed as a means of fleeing in secrecy and safety from the Vatican when the turbulent Romans or foreign invaders made the pope's life insecure and placed his city at the mercy of vandals. The "Pope's own city of Rome" should never be thought of without a mental picture of the covered passage from the episcopal palace to the fortified castle, along which popes young and old, bad and good, have hurried praying or cursing. Let us look upon some of these fugitive popes, and realise from their trembling steps, their impotent objurgations, the hunted look in their eyes, how much of dignity and liberty the possession of Rome secured to them in the exercise of their divine mission. There is a type of Catholic whose favourite theme is Canossa, as his adversary's favourite theme is the Copernican system. An emperor standing outside the Pope's castle in a penitent's shirt through weary days and icy nights beseeching him to withdraw the decree of excommunication strikes the imagination to the exclusion of the sequel of the story. Four years after the experience of Canossa, the "penitent" emperor, accompanied by his antipope, brought an army to Rome and made Gregory fly to Castel Sant' Angelo. The people abandoned the cause of the great Hildebrand, betrayed Rome to the enemy at its gates and deposed their lawful pope. But imperial vengeance for a humiliation which had been undertaken to satisfy the superstition of the vulgar did not end there. Henry V. exacted from Paschal II.